CN114724901A

CN114724901A - Circuit breaker

Info

Publication number: CN114724901A
Application number: CN202210408263.0A
Authority: CN
Inventors: 邹航; 林桌勇; 周燕海; 赖森林
Original assignee: Xiamen Hongfa Electrical Safety and Controls Co Ltd
Current assignee: Xiamen Hongfa Electrical Safety and Controls Co Ltd
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2022-07-08

Abstract

The invention relates to a circuit breaker, which comprises a base, a mechanism, a contact assembly and an arc extinguish chamber, wherein the arc extinguish chamber is arranged on one side of the contact assembly, the contact assembly comprises a fixed contact with a fixed contact and a movable contact with a movable contact, the movable contact has a movable stroke for realizing the connection or disconnection of the circuit breaker relative to the fixed contact, the mechanism is linked with the moving contact, a gas advancing path for blowing arc extinction is formed from the contact assembly to the arc extinction chamber, the moving contact or the mechanism is attached with a gas baffle plate which moves along with the movement of the moving contact, when the moving contact is disconnected relative to the static contact, the gas baffle plate follows the moving stroke of the moving contact to block the upstream of the gas traveling path, therefore, most of gas generated by electric arc between the moving contact and the static contact can move towards the arc extinguish chamber, and the electric arc is accelerated to enter the arc extinguish chamber.

Description

Circuit breaker

Technical Field

The invention relates to the field of low-voltage switching devices, in particular to improvement on an arc extinguishing function.

Background

When the movable contact and the fixed contact of the circuit breaker are disconnected, the initial distance between the movable contact and the fixed contact is small, the electric field intensity is high, electric arcs can be generated between the movable contact and the fixed contact, the electric arcs are not extinguished, the circuit cannot be completely disconnected, the temperature of the electric arcs is high, the high-temperature electric arcs can burn out equipment to cause serious accidents, and in order to extinguish the electric arcs in time, an arc extinguishing system of the circuit breaker is particularly important. The gas-blast arc extinction is an effective auxiliary arc extinction means, and the arc extinction process is accelerated by utilizing an arc ablation gas generation material to generate a large amount of gas and pushing the arc into an arc extinction chamber through the gas. However, in the prior art, the moving contact area and the fixed contact area of the circuit breaker are often open, and when a large amount of gas is generated in the moving contact area and the fixed contact area, the gas is easily dispersed to other positions in the inner cavity of the circuit breaker, so that the gas blast arc extinguishing effect is reduced.

Disclosure of Invention

Therefore, in order to solve the above problems, the present invention provides a circuit breaker with an optimized structure, in which a gas baffle is disposed to semi-close a contact region of the circuit breaker, so as to promote gas generated by an arc to rush to an arc extinguishing chamber.

The invention is realized by adopting the following technical scheme:

the invention provides a circuit breaker, which comprises a base, a mechanism, a contact assembly and an arc extinguish chamber, wherein the arc extinguish chamber is arranged on one side of the contact assembly, the contact assembly comprises a static contact with a static contact and a movable contact with a movable contact, the movable contact has a movable stroke for realizing the connection or disconnection of the circuit breaker relative to the static contact, the mechanism is in linkage connection with the movable contact, a gas traveling path for blowing arc extinction is formed from the contact assembly to the arc extinguish chamber, a gas baffle plate which moves along with the movement of the movable contact is attached to the movable contact or the mechanism, and when the movable contact is disconnected relative to the static contact, the upstream of the gas traveling path is blocked by the aid of the gas baffle plate along with the movable stroke of the movable contact.

In order to further ensure that most of a large amount of gas generated between the moving contact and the fixed contact due to the electric arc can move towards the arc extinguish chamber, in one embodiment, the base preferably comprises a first side wall and a second side wall, the contact assembly and the gas baffle are clamped between the first side wall and the second side wall, and the first side wall, the second side wall and the gas baffle form a U-shaped semi-enclosed space with an opening facing the arc extinguish chamber.

In order to accelerate the movement of the gas towards the arc extinguish chamber and improve the arc extinguish effect, in one embodiment, it is preferable that the opposite surrounding surfaces of the first side wall and the second side wall corresponding to the contact assembly are inclined surfaces inclined obliquely downward, and the two opposite surrounding surfaces form a gas pressurization channel between the contact assembly and the arc extinguish chamber, the gas pressurization channel gradually expanding from the contact assembly to the arc extinguish chamber.

In order to prevent parts of the main circuit from being damaged due to serious heating caused by overhigh arc energy, and to prevent the moving contact from being continuously burned, in one embodiment, the gas burning device preferably further comprises a moving ignition plate, one end of the moving ignition plate is arranged at the downstream of the gas traveling path and close to the moving contact, and the other end of the moving ignition plate is in equipotential connection with the moving contact.

Preferably, the width of one end of the movable arc ignition plate located at the downstream of the gas traveling path is smaller than the distance between the first side wall and the second side wall, so that one end of the movable arc ignition plate has an air gap with the first side wall and/or the second side wall.

Preferably, the stationary contact has a stationary arc-striking portion extending toward the arc-extinguishing chamber, and a convex hull is provided between the stationary contact and the stationary arc-striking portion to serve as an intermediate transition node of the electric arc to guide the electric arc at one end of the stationary contact to the stationary arc-striking portion.

Preferably, the gas baffle is made of an insulating gas generating material.

Preferably, the air baffle main body is of an arc-shaped plate structure, a pin shaft is fixedly arranged on the mechanism, the air baffle and the moving contact are in clearance fit with the pin shaft through respective shaft holes so as to be rotatably connected with the mechanism, an arc-shaped sliding rail is further arranged on the base, and the air baffle is in sliding fit in the sliding rail.

The invention has the following beneficial effects: the invention can plug the upstream space of the gas advancing path of the gas blast arc extinguishing by arranging the gas baffle plate, ensures that most of gas generated between the moving contact and the static contact due to electric arc can move towards the arc extinguishing chamber, accelerates the pushing of the electric arc into the arc extinguishing chamber, can reduce the burning time of the electric arc, reduces the energy generated by short circuit electric arc, and improves the short circuit capability of the circuit breaker. Meanwhile, the air baffle can also prevent the electric arc from reversely jetting and ablating materials or adhering caused by the main spring and the mechanism, and the problem that the opening and closing movement of a product after the product is subjected to short-circuit current is not smooth or the product cannot be opened and closed due to the adhesion of parts is avoided.

Drawings

Fig. 1 is a front view of an internal structure of the circuit breaker in the embodiment;

fig. 2 is a perspective view of an internal structure of the circuit breaker in the embodiment;

fig. 3 is a front view of the whole of the circuit breaker in the embodiment;

FIG. 4 is a cross-sectional view taken at A-A of FIG. 3;

FIG. 5 is a cross-sectional view taken at B-B of FIG. 3;

fig. 6 is an assembly view (angle one) of the moving contact, the air baffle and the mechanism in the embodiment;

fig. 7 is an assembly view (angle two) of the moving contact, the air baffle and the mechanism in the embodiment;

fig. 8 is an exploded view of the moving contact, air baffle and mechanism of the embodiment;

FIG. 9 is a schematic view of the air baffle of the embodiment slidably fitted in the slide rail;

FIG. 10 is an enlarged view of a portion of FIG. 9 at D;

fig. 11 is a cross-sectional view at C-C in fig. 9.

Detailed Description

To further illustrate the various embodiments, the invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The invention will now be further described with reference to the accompanying drawings and detailed description.

Referring to fig. 1 to 5, as a preferred embodiment of the present invention, a circuit breaker is provided, which includes a base 1, a mechanism 2, a movable contact 3, a stationary contact 4, and an arc-extinguishing chamber 6, wherein the base 1 as a circuit breaker housing has an installation cavity, and the mechanism 2, the movable contact 3, the stationary contact 4, and the arc-extinguishing chamber 6 are installed in the installation cavity. The circuit breaker also includes a handle, a trip unit, etc. to perform the basic functions of the circuit breaker. The moving contact 3 and the static contact 4 form a contact assembly of the circuit breaker, the moving contact 3 is provided with a moving contact 31, the static contact 4 is provided with a static contact 41, the moving contact 3 has a moving stroke relative to the static contact 4, and the moving stroke is used for realizing the contact or separation of the moving contact 31 and the static contact 41, so that the circuit breaker is switched on or switched off. The arc extinguishing chamber 6 is arranged at one side of the contact assembly and is used for arc extinguishing treatment of electric arc generated between the moving contact 3 and the static contact 4 due to disconnection. The mechanism 2 is linked with the moving contact 3 to realize the opening of the circuit breaker by matching with a handle, a release and the like. A gas travel path for gas-blast arc extinction is formed from the contact assembly to the arc extinguish chamber 6, namely, when the moving contact 3 and the static contact 4 are disconnected, an electric arc occurs, a large amount of gas starts to be generated from an area between the moving contact 3 and the static contact 4, and a path for the gas to be blown from the contact assembly to the arc extinguish chamber 6 is the gas travel path.

Wherein, a gas baffle plate 5 is attached on the mechanism 2, and when the moving contact 3 moves, the gas baffle plate 5 on the mechanism 2 moves along with the moving contact. And in the process of opening movement of the moving contact 3, the gas baffle 5 can block the upstream of the gas advancing path by means of the moving stroke of the moving contact 3 which follows the moving contact, and prevents a large amount of gas generated by electric arc in the region of the contact component from rushing out in the direction opposite to the arc extinguish chamber 6, so that the high air pressure between the moving contact 31 and the fixed contact 41 is ensured, most of the gas can move towards the arc extinguish chamber 6, the electric arc is accelerated to be pushed to enter the arc extinguish chamber 6, the electric arc burning time is shortened, the energy generated by short-circuit electric arc is reduced, and the short-circuit capacity of the circuit breaker is improved. Meanwhile, the air baffle 5 can also prevent the main spring and the mechanism 2 from being ablated or adhered by electric arc reverse injection, so that the problem that the opening and closing movement of the product after the product is subjected to short-circuit current is not smooth or the product cannot be opened and closed due to the adhesion of parts is avoided.

Referring to fig. 4 and 5, the base 1 includes a first sidewall 11 and a second sidewall 12, and the contact assembly and the gas baffle 5 are clamped between the first sidewall 11 and the second sidewall 12, so that the first sidewall 11, the second sidewall 12 and the gas baffle 5 form a U-shaped semi-enclosed space with an opening facing the arc extinguish chamber 6, and further ensure that most of the gas generated by the electric arc between the moving contact and the stationary contact can move towards the arc extinguish chamber 6. Furthermore, in the present embodiment, the opposing surrounding surfaces of the first side wall 11 and the second side wall 12 corresponding to the contact assembly are inclined surfaces, and two opposing surrounding surfaces form a gas pressurization channel between the first side wall 11 and the second side wall 12, which gradually expands from the contact assembly to the arc extinguishing chamber 6, so as to accelerate the movement of the gas toward the arc extinguishing chamber 6 and improve the arc extinguishing effect.

In this embodiment, the contact assembly and the arc extinguish chamber 6 are arranged oppositely, the gas flowing path blown to the arc extinguish chamber 6 from the contact assembly is almost straight towards the arc extinguish chamber 6, in other embodiments, a bent gas channel can be arranged between the contact assembly and the arc extinguish chamber 6 to guide gas, the design can enable the relative position design of the contact assembly and the arc extinguish chamber 6 to be more flexible, but the speed of the gas in the bent gas channel can be reduced, and therefore the contact assembly and the arc extinguish chamber 6 are preferably arranged oppositely.

In this embodiment, the gas baffle 5 is made of an insulating gas generating material such as nylon, melamine, and PA46, so that the gas baffle 5 can generate a large amount of gas even when the arc is burned at high temperature, thereby enhancing the arc extinguishing function.

In this embodiment, the movable stroke of the movable contact 3 is swinging, as shown in fig. 6-8, the main body of the air baffle 5 is an arc-shaped plate structure, a pin 32 is fixed on the mechanism 2, and the movable contact 3 and the air baffle 5 are both in clearance fit with the pin 32 through respective shaft holes so as to be rotatably connected with the mechanism 2. Referring to fig. 9-11, an arc-shaped slide rail 10 matching with the arc-shaped extension of the air baffle 5 is further provided on the base 1, and the air baffle 5 is slidably fitted in the slide rail 10. The air baffle 5 has a certain movable gap in the slide rail 10, when the moving contact 3 swings, the linked mechanism 2 drives the air baffle 5 to move, the movable line of the air baffle 5 is effectively limited by the slide rail 10, and the air baffle 5 can form a tight sealing effect on the upstream of the gas advancing path during the whole opening swing stroke of the moving contact 3. The air baffle 5 with the plate-shaped structure ensures the sealing effect, occupies a small space and is beneficial to yielding the installation and arrangement space of the mechanism 2. The present embodiment attaches the air baffle 5 to the mechanism 2 by the above-described assembly method, and can also simplify the installation process of the air baffle 5 and improve the assembly efficiency. In other embodiments, the air baffle 5 may be fixedly connected to the mechanism 2 or the movable contact 3, as long as the air baffle 5 can follow the moving stroke of the movable contact 3. And in this embodiment, the air baffle 5 is further provided with a reinforcing rib 51 to increase the rigidity of the air baffle 5.

As shown in fig. 1, the stationary contact 4 has a stationary arc-striking portion 42 extending toward the arc-extinguishing chamber 6, and a convex hull 7 is disposed between the stationary contact 41 and the stationary arc-striking portion 42, and the convex hull 7 can serve as an intermediate arc-striking node (springboard) and rapidly guide the arc at one end of the stationary contact 41 downward to the stationary arc-striking portion 42. The circuit breaker also comprises a movable arc striking plate 8, one end of the movable arc striking plate 8 is arranged at the downstream of the gas advancing path and is close to the movable contact 3, the other end of the movable arc striking plate is electrically connected with a wiring terminal 9 to realize equipotential connection of the movable arc striking plate 8 and the movable contact 3, when electric arcs are generated, the movable arc striking plate 8 at the downstream of the gas advancing path bears one end of the electric arc which jumps downwards under the blowing of the gas, so that parts (such as a bimetal and an electromagnetic trip coil) of a main circuit are prevented from being damaged due to overhigh heat caused by borne electric arc energy, and the movable contact 3 is also prevented from being continuously burnt. Specifically, in this embodiment, one end of the movable arc striking plate 8 close to the movable contact 3 is provided with a V-shaped bending portion 81, a tip of the V-shaped bending portion 81 and the static arc striking portion 42 are respectively disposed at two sides of the arc extinguishing chamber 6, and in a disconnected state, the tip of the V-shaped bending portion 81 is close to a connection line of the movable contact 3 and the static arc striking portion 42, so that when one end of the arc runs to the static arc striking portion 42, since the arc between the movable contact 3 and the static arc striking portion 42 is very close to the tip of the V-shaped bending portion 81, the other end of the arc can rapidly jump to the tip of the V-shaped bending portion 81 and continue to run, so that the energy of the arc of the movable contact 3 and the main circuit disappears or decreases, and the arc can be rapidly elongated in the process of the arc running by the static arc striking portion 42 and the movable arc striking plate 8, and enters the arc extinguishing chamber 6 for arc extinguishing.

In the embodiment, as shown in fig. 2, the width of the movable ignition plate 8 at the downstream end of the gas traveling path is smaller than the distance between the first side wall 11 and the second side wall 12, so that the movable ignition plate 8 at the downstream end of the gas traveling path has an air gap with the first side wall 11 and/or the second side wall 12, which does not generate too large blocking effect on the gas flow, and ensures that the gas flow can blow toward the arc extinguishing chamber 6, pushing the arc to extinguish in the arc extinguishing chamber 6.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides a circuit breaker, includes base, mechanism, contact subassembly and explosion chamber, the contact subassembly is including the static contact that has the stationary contact and the moving contact that has the moving contact, the relative static contact of moving contact has the movable stroke that realizes the circuit breaker switch-on or divide absolutely, the mechanism is connected with the moving contact linkage, certainly the contact subassembly extremely the explosion chamber forms the gas route of marcing of gas-blast arc extinguishing, its characterized in that: and when the moving contact is disconnected relative to the static contact, the moving stroke of the moving contact is followed by the air baffle to block the upstream of the gas advancing path.

2. The circuit breaker of claim 1, wherein: the base includes first lateral wall and second lateral wall, contact subassembly and gas baffle are held between first lateral wall and the second lateral wall, first lateral wall, second lateral wall and gas baffle constitute a U type, the opening is towards the semi-enclosed space of explosion chamber.

3. The circuit breaker of claim 2, wherein: the first side wall and the second side wall are inclined planes corresponding to opposite surrounding surfaces of the contact assembly, and a gas pressurization channel which is gradually enlarged from the contact assembly to the arc extinguish chamber is formed between the first side wall and the second side wall by the two opposite surrounding surfaces.

4. The circuit breaker of claim 2, wherein: the gas-flow-path-adjustable gas-flow-path switching device is characterized by further comprising a movable arc-striking plate, wherein one end of the movable arc-striking plate is arranged at the downstream of the gas-flow-path and close to the movable contact, and the other end of the movable arc-striking plate is connected with the movable contact in an equipotential mode.

5. The circuit breaker of claim 4, wherein: the width of one end of the movable ignition plate positioned at the downstream of the gas traveling path is smaller than the distance between the first side wall and the second side wall, so that one end of the movable ignition plate and the first side wall and/or the second side wall are provided with air gaps.

6. The circuit breaker of claim 1, wherein: the static contact is provided with a static arc ignition part extending towards the arc extinguish chamber, and a convex hull is arranged between the static contact and the static arc ignition part to be used as a middle transition node of electric arc to guide the electric arc at one end of the static contact to the static arc ignition part.

7. The circuit breaker of claim 1, wherein: the gas baffle is made of insulating gas generating materials.

8. The circuit breaker of claim 1, wherein: the air baffle main body is of an arc-shaped plate structure, a pin shaft is fixedly arranged on the mechanism, the air baffle and the moving contact are in clearance fit with the pin shaft through respective shaft holes so as to be rotatably connected with the mechanism, an arc-shaped sliding rail is further arranged on the base, and the air baffle is in sliding fit in the sliding rail.

9. The circuit breaker of claim 8, wherein: and the air baffle plate is provided with a reinforcing rib.